When a callchain entry has no srcline available, we ended up
comparing the instruction pointer. I consider this to be not
too useful. Rather, I think we should group the entries by
function name, which this patch adds. For people who want to
split the data on the IP boundary, using `-g address` is the
correct choice.
Before:
~~~~~
100.00% 38.86% [.] main
|
|--61.14%--main inlining.cpp:14
| std::norm<double> complex:664
| std::_Norm_helper<true>::_S_do_it<double> complex:654
| std::abs<double> complex:597
| std::__complex_abs complex:589
| |
| |--56.03%--hypot
| | |
| | |--8.45%--__hypot_finite
| | |
| | |--7.62%--__hypot_finite
| | |
| | |--2.29%--__hypot_finite
| | |
| | |--2.24%--__hypot_finite
| | |
| | |--2.06%--__hypot_finite
| | |
| | |--1.81%--__hypot_finite
...
~~~~~
After:
~~~~~
100.00% 38.86% [.] main
|
|--61.14%--main inlining.cpp:14
| std::norm<double> complex:664
| std::_Norm_helper<true>::_S_do_it<double> complex:654
| std::abs<double> complex:597
| std::__complex_abs complex:589
| |
| |--60.29%--hypot
| | |
| | --56.03%--__hypot_finite
| |
| --0.85%--cabs
~~~~~
Cc: Arnaldo Carvalho de Melo <a...@redhat.com>
Cc: David Ahern <dsah...@gmail.com>
Cc: Namhyung Kim <namhy...@kernel.org>
Cc: Peter Zijlstra <a.p.zijls...@chello.nl>
Cc: Yao Jin <yao....@linux.intel.com>
Signed-off-by: Milian Wolff <milian.wo...@kdab.com>
---
tools/perf/util/callchain.c | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)
diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c
index 3a349530fee1..211ed3713fac 100644
--- a/tools/perf/util/callchain.c
+++ b/tools/perf/util/callchain.c
@@ -619,11 +619,9 @@ enum match_result {
MATCH_GT,
};
-static enum match_result match_chain_srcline(struct callchain_cursor_node
*node,
- struct callchain_list *cnode)
+static enum match_result match_chain_strings(const char *left,
+ const char *right)
{
- const char *left = cnode->srcline;
- const char *right = node->srcline;
enum match_result ret = MATCH_EQ;
int cmp;
@@ -633,10 +631,8 @@ static enum match_result match_chain_srcline(struct
callchain_cursor_node *node,
cmp = 1;
else if (left && !right)
cmp = -1;
- else if (cnode->ip == node->ip)
- cmp = 0;
else
- cmp = (cnode->ip < node->ip) ? -1 : 1;
+ return MATCH_ERROR;
if (cmp != 0)
ret = cmp < 0 ? MATCH_LT : MATCH_GT;
@@ -651,10 +647,18 @@ static enum match_result match_chain(struct
callchain_cursor_node *node,
u64 left, right;
if (callchain_param.key == CCKEY_SRCLINE) {
- enum match_result match = match_chain_srcline(node, cnode);
+ enum match_result match = match_chain_strings(cnode->srcline,
+ node->srcline);
+
+ // if no srcline is available, fallback to symbol name
+ if (match == MATCH_ERROR && cnode->ms.sym && node->sym)
+ match = match_chain_strings(cnode->ms.sym->name,
+ node->sym->name);
if (match != MATCH_ERROR)
return match;
+
+ // otherwise fall-back to IP-based comparison below
}
if (cnode->ms.sym && sym && callchain_param.key == CCKEY_FUNCTION) {
--
2.13.0
